Requires iOS 6.0+ & Sparrow purchased from AppStore
Are you a "Sparrow" mail app user? do you prefer using it more than the classic Mail.app ? then this tweak is what you are looking for.
This tweak enables push notifications for Sparrow mail and it makes it default mail app, for example when a tweak/app inject a new mail to open in mail.app this tweak makes it open in Sparrow mail app instead of that.
To enable push or a timing push, go to Sparrow app -> Settings -> Your account, then choose how you'd like the push to work with Sparrow
to remove the tweak, simply uninstall it